Burner and mobile heating device

ABSTRACT

A burner for a mobile fuel-operated heating device, in particular for a vehicle heating device, comprising:—an evaporator receiving body for receiving an evaporator assembly for distributing and evaporating liquid fuel and—at least one fuel supply line for supplying liquid fuel to the evaporator assembly, wherein the burner has a circumferential wall with a plurality of air supply openings, and the air supply openings are arranged in at least one row, said row extending in particular in the circumferential direction. The air supply openings in the at least one row comprise at least one first air supply opening with a first opening longitudinal axis, a first inlet surface, and a first outlet surface and at least one second air supply opening with a second opening longitudinal axis, a second inlet surface, and a second outlet surface The first opening longitudinal axis forms a first angle α 1  relative to a circumferential wall normal of the first air supply opening, and the second opening longitudinal axis forms a second angle α 2  relative to a circumferential wall normal of the second air supply opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application represents the national stage entry of PCT International Patent Application No. PCT/EP2021/050066 filed on Jan. 5, 2021 and claims priority to German Patent Application No. 10 2020 100 403.6 filed Jan. 10, 2020. The contents of each of these applications are hereby incorporated by reference as if set forth in their entirety herein.

DESCRIPTION

The disclosure relates to a burner for a mobile, fuel-operated heating device, in particular for a vehicle heating device, and to a mobile, fuel-operated heating device, in particular for a vehicle heating device, and to a method for manufacturing a burner.

Burners, in particular evaporator burners, are used in particular in independent vehicle heaters and/or auxiliary heaters, especially for vehicles, that are operated with liquid fuel. In such evaporator burners, liquid fuel is fed into an evaporator via a fuel supply line. Metal fiber fleeces, for example, can be used as the evaporator itself. The evaporator soaks up liquid fuel, in particular by capillary action, and distributes liquid fuel. By means of the heat provided by a glow plug or ignition element, liquid fuel is vaporized and ignited so that combustion of the fuel can take place when air is supplied. Air supply openings are arranged in a circumferential wall for this purpose. Such an arrangement is known, for example, from DE 10 2018 111 636 A1.

According to the prior art, an evaporator burner is known from DE 10 2005 032 980 B4, which comprises a combustion chamber housing in which an evaporator medium is accommodated in a bowl-like carrier. A fuel supply line is accommodated in the bottom region of the combustion chamber housing. The combustion chamber housing has a circumferential wall which is provided with exactly one row of air supply openings arranged in the circumferential direction. The air supply openings each have a radial extension direction, i.e. parallel to a circumferential wall normal. Such a perforation of the combustion chamber has the disadvantage that fuel and air are distributed inhomogeneously in the combustion chamber and thus combustion proceeds in an undefined manner in the sense of an ideal combustion process characterized by a complete and low-emission combustion. Soot formation and greatly increased NOx emissions can occur in this process. Usually, the distribution of air and fuel and thus the combustion can be improved by an empirical design of the ventilation.

Another combustion chamber assembly is known from DE 10 2012 211 932 B3. This combustion chamber assembly has a plurality of combustion air inlet openings, of which at least one of the combustion air inlet openings has a opening longitudinal axis which is inclined with respect to a surface normal of the circumferential wall in the region of the combustion air inlet opening. The combustion air inlet openings may be arranged in a plurality of rows. In this case, the combustion air inlet openings of different rows can have different inclination angles of the opening longitudinal axes. In particular, the combustion air inlet opening is inclined to such an extent that no residual radial opening is present with respect to a view in the direction of the surface normal. At a high inclination angle greater than 40°, the penetration depth in particular is insufficient.

Another heating device for a burner operated with liquid fuel is known from DE 30 10 078 A1. The heating device has a low-pressure atomizer. The heating device has oblique swirl openings in a circumferential wall.

It is an object of the disclosure to disclose an improved burner for a mobile fuel-operated heating device and a mobile fuel-operated heating device, as well as a method for manufacturing an evaporator receiving body.

The object of the disclosure is solved with respect to the burner by the features of claim 1, with respect to the heating device by the features of claim 12, with respect to the method by the features of claim 13. Suitable embodiments result from the respective dependent claims.

The burner according to the disclosure for a mobile fuel-operated heating device, in particular for a vehicle heating device, comprises

-   -   an evaporator receiving body for receiving an evaporator         assembly for distributing and evaporating liquid fuel, and     -   at least one fuel supply line for supplying liquid fuel to the         evaporator assembly. The evaporator assembly includes at least         one evaporator. For example, an evaporator may be formed of a         metal grid or a porous material having a large surface area. For         the purposes of the present disclosure, a burner is understood         to be a component assembly, in particular a component to which         fuel and combustion air are supplied for conversion into heat,         in particular for a combustion process. The burner has a         combustion chamber. The burner has a circumferential wall with a         plurality of air supply openings. Preferably, the         circumferential wall partially bounds the combustion chamber.         The air supply openings are arranged in at least one row. The         air supply openings may lie exactly or approximately on a         straight or curved line extending along the row. In this         context, “approximately” is to be understood as meaning that the         air supply openings are unambiguously assigned to the row by an         observer, in particular that the distance of the air supply         opening from the line extending along the row is significantly         less than the distance between two air supply openings of the         row. The row may optionally extend in the circumferential         direction. With a cylindrical or conical circumferential wall,         the air supply openings of the row in this embodiment lie on a         circumferential circle. Alternatively, the row may lie on an         oblique section such that the row is oblique to the         circumferential direction. Thus, the air supply openings of the         row lie on an elliptical section of the circumferential wall.         Further, the row may extend spirally along the circumferential         wall. The air supply openings in the at least one row include at         least one first air supply opening having a first opening         longitudinal axis, a first inlet surface, and a first outlet         surface, and at least one second air supply opening each having         a second opening longitudinal axis, a second inlet surface, and         a second outlet surface.

The first opening longitudinal axis forms a first angle relative to a circumferential wall normal of the first air supply opening. The second opening longitudinal axis forms a second angle (differing from the first angle, in particular differing in magnitude from the first angle) relative to a circumferential wall normal of the second air supply opening.

In this case, the first angle and the second angle are preferably selected such that the first inlet surface overlaps at least partially with the first outlet surface and the second inlet surface overlaps at least partially with the second outlet surface in the projection direction of the circumferential wall normal. If one looks in the circumferential normal direction at an air supply opening, a continuous opening can preferably be seen at least in sections. Thus, at least two different air supply openings are arranged in the row. Such an arrangement has the advantage that a spin, a penetration depth and thus also the mixing of combustion air and fuel are considerably improved. The combustion proceeds in a more defined manner and emissions of nitrogen oxides can be reduced.

In one embodiment, the air supply openings are arranged along at least two, in particular two to four, rows in the circumferential direction of the circumferential wall, wherein each row comprises at least a first air supply opening and a second air supply opening.

In an expedient embodiment, the first angle and the second angle are at most 40°, preferably 7° to 35°, more preferably 8° to 30°.

Alternatively, exclusively the first angle may be 0°. With a first angle of 0°, the first opening longitudinal axis is aligned parallel to the circumferential wall normal.

The first angle and/or the second angle may lie in a plane spanned by the circumferential wall normal and a circumferential direction (at the location of the respective air supply opening). Alternatively or additionally, the first angle and/or the second angle can lie in a (respective) plane spanned by the respective row.

In embodiments, the first angle and/or the second angle may lie in a plane spanned by the circumferential wall normal (at the location of the respective air supply opening) and a central axis of the circumferential wall. In particular, the first angle and/or the second angle may lie in a plane spanned by the circumferential normal (at the location of the respective air supply opening) and a perpendicular to a plane spanned by the respective row.

Alternatively, the first angle and/or the second angle may be oblique to a plane (respectively the above) spanned by the circumferential wall normal and a circumferential direction at the location of the respective air supply opening. Alternatively or additionally, the first angle and/or the second angle may be oblique to a plane spanned by the respective row (of air supply openings).

In one embodiment, the air supply openings further comprise third air supply openings or third and fourth air supply openings having a third angle and optionally fourth angle different from the first angle and the second angle. The air supply openings may include a plurality of air supply openings each having a different angle. Even though in principle each air supply opening may have an angle different from all other air supply openings, the precise design of the burner, e.g. by means of flow simulation, may be costly.

In an expedient embodiment, air supply openings adjacent at least in the circumferential direction, in particular air supply openings adjacent in all directions, are air supply openings with different angles. This is achieved, for example, by an arrangement in which first and second air supply openings alternate. The next row can then start with an offset.

In particular, the air supply openings may be arranged along the circumferential direction in a periodic pattern, where in particular all rows of air supply openings have the same pattern. For example, such a pattern may be A-B-A-B; A-B-C-A-B-C, A-AB-B-A-A-B-B, A-A-B-A-A-B, A-B-C-B-A-B-C.

Further, the air supply openings may be arranged axisymmetrically with respect to the central axis of the circumferential wall.

Expediently, the air supply openings are equally spaced along the circumferential direction. In this case, only the air supply openings of a respective row can be at the same distance from one another or all rows can be at the same distance from one another.

In one embodiment, the thickness of the circumferential wall may differ at least in the region of part of the air supply openings from the thickness of the remaining circumferential wall. This may, for example, be a local thickening of the circumferential wall in the region of one, several or all of the air supply openings.

In one embodiment, the circumferential wall is arranged at an evaporator receiving body. Such an evaporator receiving body expediently has a bottom region. Advantageously, the circumferential wall extends from the bottom region. The fuel supply line may open into the bottom region of the evaporator receiving body.

The mobile heating device according to the disclosure, in particular mobile vehicle heating device, comprises a burner according to the disclosure. Such a heating device is particularly suitable for use in land vehicles.

The method according to the disclosure for manufacturing a burner, preferably a burner, in particular the above burner, comprises:

-   -   Providing a circumferential wall     -   Selecting a first angle for first air supply openings depending         on the thickness of the circumferential wall,     -   Selecting a second angle for second air supply openings         depending on the thickness of the circumferential wall,     -   arranging and inserting the first air supply openings and the         second air supply openings.

In particular, flow simulations and heat distribution simulations can be used to arrange the first and second air supply openings. For the insertion of the air supply openings, the openings may be drilled or milled, for example, or may be manufactured with the burner, in particular the evaporator receiving body, in a casting manner.

The disclosure is also explained in more detail below with respect to further features and advantages by means of the description of embodiment examples and with reference to the accompanying drawings. It shows in each case in a principle drawing:

FIG. 1 first view of an evaporator receiving arrangement;

FIG. 2 second view of the evaporator receiving arrangement of FIG. 1 ;

FIG. 3 cut along a row of air supply openings of one embodiment;

FIG. 4 cut along a row of air supply openings of an alternative embodiment;

FIG. 5 partial cut perpendicular to a row of air supply openings of one embodiment,

FIG. 6 partial cut perpendicular to a row of air supply openings of an alternative embodiment.

FIG. 1 shows a first view of an evaporator receiving body 2 and a fuel supply line 4. The evaporator receiving body 2 has a bottom region 6. The fuel supply line 4 opens into the bottom region 6. The fuel supply line 4 can, for example, be designed as a tube. In the illustrated representation, the bottom region 6 has a recess which is suitable for receiving an evaporator assembly, in particular the evaporator.

A circumferential wall 8 extends from the bottom region 6. The circumferential wall is cylindrical in sections and conical in sections. An exclusively cylindrical design is also possible as an alternative. In a lower section of the circumferential wall, i.e. close to the bottom region 6, a receiving element 10 is arranged, which is suitable for receiving an ignition element and/or a flame guard. The height of the receiving element 10, measured from the bottom region, is in particular adapted to the size of the evaporator assembly.

A plurality of air supply openings 12 are provided in the circumferential wall 8. In the example shown, the air supply openings 12 are arranged in two rows 20, 22 in the circumferential direction. However, arrangement in only one row or in multiple rows is also possible. In FIG. 1 , the number of air supply openings 12 in the row 20 is greater than in the row 22, which is also visible in particular in the view according to FIG. 2 . In the row 20, moreover, the distance between the air supply openings 12 varies.

Here, in the row 22, first and second air supply openings 14, 15 are arranged as air supply openings, and in the row 20, third and fourth air supply openings 16, 17 are arranged as air supply openings.

The first air supply opening 14 is designed here with a first angle α1 of 0°. In this case, the circumferential wall normal, i.e. the perpendicular of the circumferential wall, in the area of the air supply opening and a first opening longitudinal axis are parallel to each other. With a cylindrical air supply opening, the first inlet surface and the first outlet surface completely overlap in projection along the circumferential wall normal.

Here, the second air supply opening 15 is formed at an angle. The second opening longitudinal axis 15 a of the second air supply opening and the circumferential wall normal 8 a in the region of the second air supply opening 15 are at a second angle α2 to each other. In this case, this second angle α2 lies exclusively in a plane spanned by the circumferential wall normal 8 a and the circumferential direction. When the second air supply opening 15 is cylindrical, the second inlet surface 15 b and the second outlet surface 15 c partially overlap in projection along the circumferential wall normal 8 a.

Here, the third air supply opening 16 is formed with a third angle α3 of 0°. In this case, the circumferential wall normal 8 a, i.e., the perpendicular of the circumferential wall 8, in the region of the air supply opening and a third opening longitudinal axis 16 a are parallel to each other. With the air supply opening being cylindrical, the third inlet surface 16 b and the third outlet surface 16 c completely overlap in projection along the circumferential wall normal 8 a.

The fourth air supply opening 17 is formed obliquely here. The fourth opening longitudinal axis 17 a of the fourth air supply opening 17 b and the circumferential wall normal 8 a in the region of the fourth air supply opening are at a fourth angle α4 to each other. In this case, this fourth angle α4 lies exclusively in a plane spanned by the circumferential wall normal 8 a and the central axis. With the fourth air supply opening 17 being cylindrical, the fourth inlet surface 17 b and the fourth outlet surface 17 c partially overlap in projection along the circumferential wall normal 8 a.

FIG. 3 shows an exemplary sectional view of a row of air supply openings. The air supply openings are arranged in a circumferential wall having a uniform thickness t of the wall. In the cut shown, first air supply openings 14, second air supply openings 15 and third air supply openings 16 are arranged periodically. The periodicity here is A-B-CA-B-C . . . . In this figure, the angles α1, α2 and α3 are to be exclusively in the plane shown. Here, the first air supply opening 14 is perpendicular to the circumferential wall 8. Thus, circumferential wall normal 8 a and first opening longitudinal axis 14 a are superimposed. The first outlet surface 14 c of the first air supply opening 14 is arranged on the inner side of the circumferential wall, and the first inlet surface 14 b is arranged on the outer side of the circumferential wall 8. The first inlet surface 14 b and the first outlet surface 14 c completely overlap in projection along the circumferential wall normal 8 a.

The second air inlet opening 15 extends obliquely. Thus, circumferential wall normal 8 a and second opening longitudinal axis 15 a lie one above the other at a second angle α2 to each other. The second outlet surface 15 c of the second air supply opening 15 is arranged on the inner side of the circumferential wall 8, and the second inlet surface 15 b is arranged on the outer side of the circumferential wall 8. The second inlet surface 15 b and the second outlet surface 15 c partially overlap in projection along the circumferential wall normal 8 a. Thus, an opening is provided as viewed along the circumferential wall normal 8 a.

The third air supply opening 16 extends obliquely. Thus, circumferential wall normal 8 a and third opening longitudinal axis 16 a lie one above the other at a third angle α3 with respect to each other. The third outlet surface 16 c of the third air supply opening 16 is arranged on the inner side of the circumferential wall 8, and the third inlet surface 16 b is arranged on the outer side of the circumferential wall 8. The third inlet surface 16 b and the third outlet surface 16 c partially overlap in projection along the circumferential wall normal 8 a. Thus, an opening is provided in the viewing direction along the circumferential wall normal 8 a.

FIG. 4 shows an exemplary cut through a series of air supply openings of an evaporator receiving body of an alternative embodiment. The air supply openings here have a periodicity of A-B-A-C-A-B-A . . . , i.e. a first air supply opening 14 is followed by a second air supply opening 15. This is followed by another first air supply opening 14 followed by a third air supply opening 16. The first air supply opening has the angle α1, the second air supply opening has the angle α2 and the third air supply opening has the angle α3, where here α1 is not equal to α2 and α3.

FIG. 5 shows a section of cut perpendicular to a row in which the air supply openings have a tilt component, i.e., in the plane spanned by the central axis and circumferential normal 8 a. In the embodiment shown, in a cylindrical portion of the circumferential wall, a first air supply opening 14 is arranged with a horizontal opening longitudinal axis 14 a parallel to the circumferential wall normal. A third air supply opening 16 is arranged in a conical region of the circumferential wall 8, which has a opening longitudinal axis that forms the angle α3 to the circumferential wall normal 8 a in the cut plane.

FIG. 6 shows a section cut through an alternative embodiment perpendicular to a row in which the air supply openings have a tilt component, i.e., an angle in the plane spanned by the central axis and circumferential normal 8 a. In the embodiment shown, a second air supply opening 15 having an opening longitudinal axis 15 a inclined with respect to the circumferential wall normal 8 a is disposed in a cylindrical portion of the circumferential wall. A fourth air supply opening 17 is arranged in a conical region of the circumferential wall 8, which has a horizontal opening longitudinal axis 17 a forming the angle α4 to the circumferential wall normal 8 a in the cut plane.

Even though the disclosure is illustrated using the example of a burner with an evaporator receiving body, a circumferential wall with the air supply openings described above can also be arranged elsewhere in the burner, for example with a housing, as a separate component.

REFERENCE NUMERALS

-   -   2 evaporator receiving body     -   4 fuel supply line     -   6 bottom region     -   8 circumferential wall     -   8 a circumferential wall normal     -   10 receiving element     -   12 air supply opening     -   14 first air supply opening     -   14 a first opening longitudinal axis     -   14 b first inlet surface     -   14 c first outlet surface     -   15 second air supply opening     -   15 a second opening longitudinal axis     -   15 b second inlet surface     -   15 c second outlet surface     -   16 third air supply opening     -   16 a third opening longitudinal axis     -   16 b third inlet surface     -   16 c third outlet surface     -   17 fourth air supply opening     -   17 a fourth opening longitudinal axis     -   17 b fourth inlet surface     -   17 c fourth outlet surface     -   20 row     -   22 row     -   α1 first angle     -   α2 second angle     -   α3 third angle     -   α4 fourth angle     -   t thickness 

1. A burner for a mobile fuel-operated vehicle heating device, comprising an evaporator receiving body for receiving an evaporator assembly for distributing and evaporating liquid fuel, and at least one fuel supply line for supplying liquid fuel to the evaporator assembly, wherein the burner has a circumferential wall with a plurality of air supply openings, the air supply openings being arranged in at least one row extending in a circumferential direction, wherein the air supply openings in the at least one row comprise at least one first air supply opening with a first opening longitudinal axis, a first inlet surface and a first outlet surface, and at least one second air supply opening with a second opening longitudinal axis, a second inlet surface and a second outlet surface, wherein the first opening longitudinal axis forms a first angle α1 to a circumferential wall normal to the first air supply opening, and wherein the second opening longitudinal axis forms a second angle α2, different from the first angle α1, to a circumferential wall normal to the second air supply opening.
 2. The burner according to claim 1, wherein the first angle α1 and/or the second angle α2 are selected such that the first inlet surface and the first outlet surface or the second inlet surface and the second outlet surface, respectively, at least partially overlap in the projection direction of the circumferential wall normal.
 3. The burner according to claim 1, wherein the air supply openings are arranged along at least two rows in the circumferential direction of the circumferential wall, each row comprising at least one first air supply opening and one second air supply opening.
 4. The burner according to claim 1, wherein the first angle α1 and/or the second angle α2 are at most 40°, and/or wherein exclusively the first angle α1 is 0°.
 5. The burner according to claim 1, wherein the first angle α1 and/or the second angle α2 lie in a plane spanned by the circumferential wall normal and a circumferential direction at the location of the respective air supply opening, and/or wherein the first angle α1 and/or the second angle α2 lie in a plane spanned by the respective row, or wherein the first angle α1 and/or the second angle α2 lie in a plane spanned by the circumferential wall normal at the location of the respective air supply opening and a central axis of the circumferential wall, or wherein the first angle α1 and/or the second angle α2 are oblique to a plane spanned by the circumferential wall normal and a circumferential direction at the location of the respective air supply opening, and/or wherein the first angle α1 and/or the second angle α2 are oblique to a plane spanned by the respective row.
 6. The burner according to claim 1, wherein the air supply openings further comprise third air supply openings or third and fourth air supply openings having a third angle α3 and optionally fourth angle α4 different from the first angle α1 and the second angle α2, or wherein the air supply openings comprise a plurality of air supply openings having different angles.
 7. The burner according to claim 1, wherein air supply openings adjacent at least in the circumferential direction, in particular adjacent air supply openings, are air supply openings with different angles.
 8. The burner according to claim 1, wherein the air supply openings are arranged along the circumferential direction in a periodic pattern, wherein in particular all rows of air supply openings have the same pattern.
 9. The burner according to claim 1, wherein the air supply openings are arranged at an equal distance along the circumferential direction.
 10. The burner according to claim 1, wherein the thickness of the circumferential wall at least in the region of a part of the air supply openings differs from the thickness of the remaining circumferential wall.
 11. The burner according to claim 1, wherein the circumferential wall is arranged on an evaporator receiving body having a bottom region.
 12. A mobile vehicle heating device, comprising a burner according to claim
 1. 13. A method of manufacturing a burner according to claim 1, comprising, providing a circumferential wall, selecting a first angle α1 for first air supply openings depending on the thickness (t) of the circumferential wall, selecting a second angle α2 for second air supply openings depending on the thickness (t) of the circumferential wall-, arranging and inserting the first and second air supply openings in the circumferential wall.
 14. The burner according to claim 1 wherein the air supply openings are arranged two to four rows in the circumferential direction of the circumferential wall, each row comprising at least one first air supply opening and one second air supply opening. 